Linux System Administrator

Linux Systems Administrator / Technical Operations Engineer

Location: Vadodara (HQ) | Full-time, On-site

Experience: 3–5 years

About the Role

Phonon is looking for a hands-on Technical Operations Engineer to own one or more of the aspects related to our systems including: security, reliability, scalability and cost efficiency of our technology infrastructure.

The role covers CloudOps, TechOps, DevOps, SecOps and FinOps, spanning our predominantly AWS-based cloud environment, Linux/network infrastructure and SIP/VoIP telephony platforms. The role will also lead resolution of complex cloud and production support issues.

Key Responsibilities

• Own and operate highly available, secure and scalable AWS infrastructure.
• Manage Linux, networking, VPNs, firewalls, load balancers and telephony infrastructure.
• Own Asterisk, FreePBX, OpenSIPS, SIP/RTP, SIP trunks, IVRs, diallers and hosted PBX environments.
• Drive DevOps, CI/CD, Infrastructure as Code, containerisation and operational automation.
• Own infrastructure security, vulnerability management, patching, IAM, hardening, backup/DR and ISO 27001 readiness.
• Establish monitoring, alerting, incident management and RCA practices.
• Drive FinOps, including AWS utilisation, rightsizing and cloud cost optimisation.
• Lead complex production incidents and cloud/infrastructure support escalations.
• Lead and mentor the Cloud/Technical Operations team.

Technology Stack

• Linux & Networking: RHEL/CentOS/Ubuntu, TCP/IP, DNS, routing, NAT, VPN, firewalls, SSL/TLS, load balancing
• Cloud: AWS – EC2, VPC, RDS, S3, ELB/ALB, Auto Scaling, Route 53, CloudFront, IAM, CloudWatch, CloudTrail, Lambda, SNS
• Telephony: Asterisk, FreePBX, OpenSIPS, SIP, RTP, SIP Trunking, IVR, Diallers, Hosted PBX
• DevOps: Terraform, CloudFormation, Ansible, AWS CLI, Docker, Kubernetes, Git, Jenkins/GitLab CI/GitHub Actions
• Observability: Prometheus, Grafana, Loki, ELK/EFK, Nagios, CloudWatch
• Security: IAM/RBAC, encryption, secrets management, vulnerability management, infrastructure hardening, ISO 27001

Candidate Profile

• 3-5 years across cloud infrastructure, Linux, networking, DevOps and technical operations.
• Strong hands-on experience managing AWS production environments.
• Strong Linux and networking fundamentals with experience operating high-availability systems.
• Telecom/SIP/VoIP experience is strongly preferred.
• Strong troubleshooting skills across cloud → network → Linux → application → telephony.
• Experience leading technical teams and handling critical production incidents.

Preferred Certifications: RHCE and CCNA; AWS certification is an advantage.

We are looking for a hands-on technology operations owner who can troubleshoot critical infrastructure issues while building a secure, reliable, scalable and cost-efficient operations function.